The pipeline snippet above serializes the SAX events of the
announcment document resource to plain text.

Input document of the text serializer must be valid XML document. It
should have at least one element, root element, which will contain
all the text of the document. Root element will be ignored by text
serializer and will not go into the output stream.

Further Reading

As text Serializer uses the XML serializer internally, you might
want to read the complete list of valid XML configuration parameters.
It is available at XML serializer
user documentation.